Recently, steams have various applications in areas including cleaning, humidification, cooking and aesthetic management. In particular, when sprayed onto skin, steam can remove wastes in the pores of the skin or old keratin cells. Accordingly, a steam supplying device is widely used not only in skin care clinics such as dermatology or skin care shops, but also at homes.
A conventional steam generator generally employs an electrostatic atomization method. A steam generator employing the electrostatic atomization method includes a reservoir in which water is stored, and a discharge electrode and an opposite electrode positioned in the reservoir. The steam generator atomizes the liquid in the vicinity to the discharge electrode, by applying high voltage to the discharge electrode. The atomized liquid, which is so-called ‘steam’, is supplied to a user.
Such atomization-type steam generator has a limit in its compactness due to need for separate electrodes.
Further, in a steam generator that atomizes water by applying high voltage, in addition to the steam, ozone is generated and ejected. As the linkage between the high ozone concentration and adverse effect to human health have already been well known through a plurality of researches, issues have arisen regarding safety and reliability of the device.
This steam generator employing electrostatic atomization method has no choice but to be separately equipped with a device to reduce ozone concentration, which in turn causes large-sized device and increased production cost. There is another shortcoming that the device consumes a considerable amount of power.
Accordingly, a method of generating steams by heating raw water can be used. However, this heating-type steam generator has unstable overheated regions in the process of heating the raw water introduced into a housing, and these overheated regions cause the raw water existing in the housing to be pushed up.
As described, the ascending raw water along sidewalls inside the housing undergoes instant gasification when contacted with the sidewalls that are heated to high temperature, resulting in rapid rise of the pressure inside the housing and release of strong steam (i.e., bumping) outside the housing.
Meanwhile, an example of a method to enable stable operation of a steam oven employing a steam generator is disclosed in Korean Patent Application Publication No. 10-2008-0065134 (KR 2008-0065134). This document provides a water level sensor to stably sense variations in water level, and a steam generator having the same, and a cooking device having the steam generator, and proposes that the water level sensor having one electrode is installed on a steam receptacle that stores water necessary for steam generation to stably sense the variations in the water level, irrespective of whether or not scale is generated.
In the above document, installing the water level sensor can enable stable operation of the steam generator. However, the document does not specifically describe how the issues of the gas explosion caused due to the abrupt gasification of the supplied raw water and pressure rise are addressed. Accordingly, the issues of stability and reliability of the device described above remain to be studied further.
(Patent Document 1) JP 2011-67725 A
(Patent Document 2) KR 2008-0065134 A